"Imagine that you can be at home in the morning and watch half of the news bulletin, then pick up your phone, head out, click play and it resumes from where you left off," says Anthony Rose, who heads the iPlayer online broadcasting project for the BBC. But if that sounds ambitious, it's only the start.

Speaking at Adobe's MAX conference in Milan last week, he also explained his ideas about "Broadcast 2.0", a new phase that marries internet video with social media: "Early next year you'll see the emergence of a sign-in system, an online library, and a system that lets you talk about BBC programmes with friends. This year, thanks to on-demand, you can choose what to watch, but you are probably choosing the same stuff that we put there the night before. Next year, it's your friends who are going to choose what you watch."

However, Rose's plans - which include high definition (HD) content in the near term - will either spell higher broadband prices, or a splintering of broadband provision into packages. Pricier packages would allow you to download or stream as much BBC content as you want, and cheaper ones wouldn't - rather as already happens on the limited home broadband packages which charge per gigabyte beyond a given amount.

Rose says that upcoming iPlayer features, such as ratings and discussions, will be restricted to networks of friends, rather than made public. "Rating works really well in YouTube where you've got a million videos. In iPlayer, if you rate Parliament channel as zero stars, are you saying that Parliament is rubbish, or that you just don't want to watch Parliament? Rating in the context of the BBC is very useful, but only when you've got a friends network."

These features will be part of a new iPlayer roll-out. The original iPlayer, launched in December 2007 after an extended period of public tests, came in two forms. The first uses a Windows-only peer-to-peer download system, and attracted complaints from users with Mac or Linux computers: more than 16,000 people signed an electronic petition asking for a more open system. In response, the BBC created a streaming version of iPlayer, based on Adobe's Flash, which runs on Windows, Mac and Linux.

This month, the BBC will replace the download player with new cross-platform software that runs on the desktop, though using the Flash-based - and Windows- and Mac-compatible - Adobe Integrated Runtime (AIR) rather than Windows Media. "The plan is to dual-run our new Adobe AIR-powered iPlayer alongside our existing download manager for a few months, until we're confident that the new platform works and can scale," says Rose. Towards the end of February, the Windows player will be withdrawn.

Despite these moves, the BBC is not using Flash for all its online broadcasting, as some supported devices, including Apple's iPhone, do not include Flash. Another requirement is digital rights management (DRM) to make downloaded content expire. "Although we'd love that every device supported the same playback technology, that's not the case," says Rose. "So what we've done is to build a flexible delivery platform that can encode each piece of content in at least 10 different formats and bitrates. For DRM, we support Microsoft DRM, we support OMA (Open Mobile Alliance), and we now support Adobe DRM. An iPhone has Apple DRM, so we're trying to work with the folks at Apple, but that hasn't happened yet. On Nokia we use OMA, and on Windows mobile devices we use Windows."

Why did the BBC choose Flash rather than Microsoft's Silverlight media player, which is also cross-platform (though its Linux support is left to a third-party and lags behind)? "We wanted the site to 'just work' when people get there. Pretty much 100% of computers have Flash installed versus only a small percentage for Silverlight, making this an easy decision," says Rose, adding diplomatically that he "may re-evaluate" if there is good reason in future.

But rich content means heavy demands on bandwidth: along with other BBC Flash content, the BBC iPlayer now accounts for almost 10% of UK internet bandwidth at peak time, says Rose. That figure is likely to increase, as the BBC adds better device support and more features. "We're going to add HD [video], we're going to add podcasts, we're going to add a delivery notification system. You'll see a system tray pop-up: Top Gear, next episode now out."

And who will pay for all that data transfer? You will. Rose has little patience with ISPs that complain the BBC is consuming too much bandwidth. "It's a profit centre. There is a huge opportunity for ISPs to sell people the packages they really want to get a great iPlayer experience."

James Blessing at ISPA, the UK ISP trade association, is less positive. "The BBC is getting funded for this, and then ISPs are having to pay, partly because they're moving on to a commercial distribution platform which refuses to peer," he told the Guardian, referring to the BBC's choice of content distribution network.

Receiving data from the data distributor Level 3, used for HD in iPlayer, is more expensive for ISPs than Level 3's rival Akamai. Blessing says ISPs may have to block access on the cheaper broadband packages, but adds: "People have already paid to access the BBC, so from a political point of view, service providers are really not keen to go down that road."

What's the alternative? "The other option is that people move from an unlimited all-you-can eat model to a consumption model where you pay for the amount transferred." However you spin it, the growth of internet broadcasting, which is still in its early days, will drive upgrades to more expensive broadband packages - or to overall higher prices.

The BBC's iPlayer launched one year ago this week, so in celebration the BBC is holding an iPlayer fest this Friday posting hourly features on the Internet Blog with guest comment, interviews - and maybe even some nuts-and-bolts diagrams